Solvent extraction separation of thorium(IV) with 2-ethyl hexyl phosphonic acid mono-2-ethyl hexyl ester (PC-88A)

Solvent extraction separation of thorium(IV) has been carried out with 2-ethyl hexyl phosphonic acid mono-2-ethyl hexyl ester (PC-88A) in toluene from nitric acid media. Various parameters like acid concentration, reagent concentration, diluent, stripping agent, equilibrium time and diverse ions affecting the extraction of thorium(IV) were studied systematically. Thorium was quantitatively extracted from 0.1-1.0 M nitric acid with 1 x 10-2 M PC-88A in toluene. It was then stripped out from the organic phase with 10 M nitric acid and determined spectrophotometrically by thoron method. Further, the separation of thorium was carried out from uranium, lanthanum and cerium depending on the difference in the extraction behaviour of these metals with PC-88A. (author)